CDK2 and hepatocellular carcinoma: While phosphorylation on Thr187 by Cdk2/cyclin E complexes is essential for its ubiquitination and degradation, p27 is also phosphorylated by PKB/AKT on Thr157 in HCC, inducing its relocalization to the cytoplasm and impairing its negative effect on nuclear Cdk/cyclin complexes (Figure 7) [223,224].